Recently, various types of illumination devices employing polymer dispersed liquid crystal (hereinafter called “PDLC”) capable of switching a diffusing state of diffusing incident light and a transmitting state of transmitting incident light have been proposed. A light guide propagates light from a light source. On the light guide, the propagated light may leak at an end portion on a side opposite to a light incident surface.
In contrast, various display devices employing PDLC have been reviewed in recent years.